CHICOS developed a Europe-wide strategy for mother-child cohort research by evaluating current birth cohort data across Europe and comparing alternatives for future strategies. CHICOS has shown that the groundwork now exists for ongoing birth cohort research in Europe including more than 500,000 mother-child pairs which can lead to scientific advances of great relevance to European child health policy making. CHICOS recommends establishing a collaborative European Birth Cohort infrastructure, using data from existing and new cohorts. Such a cohort will lead to a permanent, Europe-wide data resource containing longitudinal, individual-level information about child health in Europe. It will provide key statistics on child health and determinants to enable health surveillance and to provide rapid responses to knowledge gaps that have to be tackled to inform policies.
In the last two decades, a number of new pregnancy and birth cohorts have been established in Europe which share the purpose to follow participants from the intrauterine period, throughout childhood and adolescence into early adulthood. There are several unique features of the birth cohort study design that make it particularly important as a contribution to understand the causes of disease and ill-health. Cohort studies have been particularly important in establishing causal relationships in areas where for practical or ethical reasons randomised controlled trials are not possible, such as maternal cigarette smoking, foetal and infant growth, or environmental toxin exposure. However, data are, by nature, fragmented across cohorts and improved coordination at European level is needed to take full advantage of this important infrastructure of existing cohorts.
CHICOS aimed to develop an integrated strategy for mother-child cohort research through the coordination of important European birth cohorts.
CHICOS compiled an inventory of all birth cohorts in Europe. This shows that the number of birth cohorts exceeds 70 and they encompass more than 500,000 children (Larsen et al, 2013; Figure 1). Most cohorts were located in Northern and Western Europe, though all regions of Europe have birth cohorts that are suitable for research purposes. The inventory, including an overview of the data collected by these cohorts can be found at www.birthcohorts.net, a webpage that aims to make relevant basic information available to the public, to stakeholders and to researchers in order to increase the scientific exploitation of these valuable data as well as facilitate collaboration and comparative analyses between the studies.
Further, CHICOS evaluated available data on health outcomes (working groups, WGs, on birth outcomes, asthma, respiratory health and allergies, growth and obesity, neurodevelopment, injuries, cancer, and infections) and determinants (WGs on social, dietary, life-style, environmental, and genetic factors) in the European birth cohorts, identifying common gaps such as lack of studies in Eastern Europe and minority populations, lack of harmonization in methods, and lack of follow-up in older children (http://www.chicosproject.eu/pubs-docs/). CHICOS carried out 8 studies on important public health issues in which data from many birth cohorts have been combined successfully to give larger analysis populations and thus more conclusive findings than those based on single cohorts
Based on the evaluations, CHICOS has prepared a strategic document recommending the establishment of a collaborative European Birth Cohort infrastructure, using data from existing and new cohorts (http://www.chicosproject.eu/pubs-docs/2013/05/23/chicos-strategic-document/). It would include a database platform, data sharing and harmonisation rules, biobank access guidelines, exchange of methods and expertise – resulting in more efficient use of existing and newly established cohorts. This will lead to permanent Europe-wide data resource containing longitudinal, individual-level information about child health in Europe.
CHICOS has already strengthened collaboration amongst mother-child cohort studies throughout Europe. New cohorts continue to express interest in participation. This shows that CHICOS has built the groundwork for ongoing birth cohort research in Europe including more than 500,000 mother-child pairs which can lead to scientific advances of great relevance to European child health policy making.
In fact, currently there is no common European database with prospective, individual-level, data on child health and determinants. The infrastructure recommended by CHICOS will provide key statistics on child health and determinants to enable health surveillance and to provide rapid responses to knowledge gaps that have to be tackled to inform policies.